[INFO] fetching crate lgio 0.1.0...
[INFO] checking lgio-0.1.0 against try#4f260f0f20b3133d20cfb50353c0221943af5796+rustflags=-Dunmustuse_in_always_ok for pr-148577
[INFO] extracting crate lgio 0.1.0 into /workspace/builds/worker-4-tc2/source
[INFO] started tweaking crates.io crate lgio 0.1.0
[INFO] finished tweaking crates.io crate lgio 0.1.0
[INFO] tweaked toml for crates.io crate lgio 0.1.0 written to /workspace/builds/worker-4-tc2/source/Cargo.toml
[INFO] validating manifest of crates.io crate lgio 0.1.0 on toolchain 4f260f0f20b3133d20cfb50353c0221943af5796
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+4f260f0f20b3133d20cfb50353c0221943af5796" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+4f260f0f20b3133d20cfb50353c0221943af5796" "generate-lockfile" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+4f260f0f20b3133d20cfb50353c0221943af5796" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc2/source:/opt/rustwide/workdir:ro,Z" "-v" "/var/lib/crater-agent-workspace/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/var/lib/crater-agent-workspace/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--user" "0:0" "--network" "none" "ghcr.io/rust-lang/crates-build-env/linux@sha256:4848fb76d95f26979359cc7e45710b1dbc8f3acb7aeedee7c460d7702230f228" "/opt/rustwide/cargo-home/bin/cargo" "+4f260f0f20b3133d20cfb50353c0221943af5796" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 0ded1eda7ec6e17385ea54efc41f163683b4a943afa7cf2e10df1812bf080756
[INFO] running `Command { std: "docker" "start" "-a" "0ded1eda7ec6e17385ea54efc41f163683b4a943afa7cf2e10df1812bf080756", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "0ded1eda7ec6e17385ea54efc41f163683b4a943afa7cf2e10df1812bf080756", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "0ded1eda7ec6e17385ea54efc41f163683b4a943afa7cf2e10df1812bf080756", kill_on_drop: false }`
[INFO] [stdout] 0ded1eda7ec6e17385ea54efc41f163683b4a943afa7cf2e10df1812bf080756
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc2/source:/opt/rustwide/workdir:ro,Z" "-v" "/var/lib/crater-agent-workspace/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/var/lib/crater-agent-workspace/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=forbid -Dunmustuse_in_always_ok" "-e" "RUSTDOCFLAGS=--cap-lints=forbid" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--user" "0:0" "--network" "none" "ghcr.io/rust-lang/crates-build-env/linux@sha256:4848fb76d95f26979359cc7e45710b1dbc8f3acb7aeedee7c460d7702230f228" "/opt/rustwide/cargo-home/bin/cargo" "+4f260f0f20b3133d20cfb50353c0221943af5796" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] ffd70b0206bb5c2682843ea68850a0614c414af4a830cd0a92e693b1234d71a5
[INFO] running `Command { std: "docker" "start" "-a" "ffd70b0206bb5c2682843ea68850a0614c414af4a830cd0a92e693b1234d71a5", kill_on_drop: false }`
[INFO] [stderr]     Checking lgio v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] error: this type will no longer be must used: Result<&[u8], Infallible>
[INFO] [stdout]   --> src/sync_impls.rs:19:62
[INFO] [stdout]    |
[INFO] [stdout] 19 |       fn fill_buf(&mut self) -> Result<&[u8], Self::ReadError> {
[INFO] [stdout]    |  ______________________________________________________________^
[INFO] [stdout] 20 | |         Ok(*self)
[INFO] [stdout] 21 | |     }
[INFO] [stdout]    | |_____^
[INFO] [stdout]    |
[INFO] [stdout]    = note: requested on the command line with `-D unmustuse-in-always-ok`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: this type will no longer be must used: Result<&[u8], Infallible>
[INFO] [stdout]   --> src/sync_impls.rs:20:9
[INFO] [stdout]    |
[INFO] [stdout] 20 |         Ok(*self)
[INFO] [stdout]    |         ^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: this type will no longer be must used: Result<&[u8], Infallible>
[INFO] [stdout]   --> src/sync_impls.rs:31:62
[INFO] [stdout]    |
[INFO] [stdout] 31 |       fn fill_buf(&mut self) -> Result<&[u8], Self::ReadError> {
[INFO] [stdout]    |  ______________________________________________________________^
[INFO] [stdout] 32 | |         Ok(*self)
[INFO] [stdout] 33 | |     }
[INFO] [stdout]    | |_____^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: this type will no longer be must used: Result<&[u8], Infallible>
[INFO] [stdout]   --> src/sync_impls.rs:32:9
[INFO] [stdout]    |
[INFO] [stdout] 32 |         Ok(*self)
[INFO] [stdout]    |         ^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: this type will no longer be must used: Result<&[u8], Infallible>
[INFO] [stdout]   --> src/sync_impls.rs:76:62
[INFO] [stdout]    |
[INFO] [stdout] 76 |       fn fill_buf(&mut self) -> Result<&[u8], Self::ReadError> {
[INFO] [stdout]    |  ______________________________________________________________^
[INFO] [stdout] 77 | |         Ok(&[])
[INFO] [stdout] 78 | |     }
[INFO] [stdout]    | |_____^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: this type will no longer be must used: Result<&[u8], Infallible>
[INFO] [stdout]   --> src/sync_impls.rs:77:9
[INFO] [stdout]    |
[INFO] [stdout] 77 |         Ok(&[])
[INFO] [stdout]    |         ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: this type will no longer be must used: Result<&[u8], Infallible>
[INFO] [stdout]    --> src/sync_impls.rs:100:62
[INFO] [stdout]     |
[INFO] [stdout] 100 |       fn fill_buf(&mut self) -> Result<&[u8], Self::ReadError> {
[INFO] [stdout]     |  ______________________________________________________________^
[INFO] [stdout] 101 | |         Ok(&[])
[INFO] [stdout] 102 | |     }
[INFO] [stdout]     | |_____^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: this type will no longer be must used: Result<&[u8], Infallible>
[INFO] [stdout]    --> src/sync_impls.rs:101:9
[INFO] [stdout]     |
[INFO] [stdout] 101 |         Ok(&[])
[INFO] [stdout]     |         ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `lgio` (lib) due to 8 previous errors
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stdout] error: this type will no longer be must used: Result<&[u8], Infallible>
[INFO] [stdout]   --> src/adapters/take.rs:63:20
[INFO] [stdout]    |
[INFO] [stdout] 63 |         assert_eq!(reader.fill_buf().unwrap_or_else(|infallible| match infallible {}), &[]);
[INFO] [stdout]    |                    ^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: requested on the command line with `-D unmustuse-in-always-ok`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: this type will no longer be must used: Result<&[u8], Infallible>
[INFO] [stdout]   --> src/adapters/take.rs:72:20
[INFO] [stdout]    |
[INFO] [stdout] 72 |         assert_eq!(reader.fill_buf().unwrap_or_else(|infallible| match infallible {}), &[1]);
[INFO] [stdout]    |                    ^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: this type will no longer be must used: Result<&[u8], Infallible>
[INFO] [stdout]   --> src/adapters/take.rs:74:20
[INFO] [stdout]    |
[INFO] [stdout] 74 |         assert_eq!(reader.fill_buf().unwrap_or_else(|infallible| match infallible {}), &[]);
[INFO] [stdout]    |                    ^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: this type will no longer be must used: Result<&[u8], Infallible>
[INFO] [stdout]   --> src/adapters/chain.rs:52:20
[INFO] [stdout]    |
[INFO] [stdout] 52 |         assert_eq!(reader.fill_buf().unwrap_or_else(|infallible| match infallible {}), &[]);
[INFO] [stdout]    |                    ^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: this type will no longer be must used: Result<&[u8], Infallible>
[INFO] [stdout]   --> src/adapters/chain.rs:53:20
[INFO] [stdout]    |
[INFO] [stdout] 53 |         assert_eq!(reader.fill_buf().unwrap_or_else(|infallible| match infallible {}), &[]);
[INFO] [stdout]    |                    ^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: this type will no longer be must used: Result<&[u8], Infallible>
[INFO] [stdout]   --> src/adapters/chain.rs:54:20
[INFO] [stdout]    |
[INFO] [stdout] 54 |         assert_eq!(reader.fill_buf().unwrap_or_else(|infallible| match infallible {}), &[]);
[INFO] [stdout]    |                    ^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: this type will no longer be must used: Result<&[u8], Infallible>
[INFO] [stdout]   --> src/adapters/chain.rs:60:20
[INFO] [stdout]    |
[INFO] [stdout] 60 |         assert_eq!(reader.fill_buf().unwrap_or_else(|infallible| match infallible {}), &[42]);
[INFO] [stdout]    |                    ^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: this type will no longer be must used: Result<&[u8], Infallible>
[INFO] [stdout]   --> src/adapters/chain.rs:62:20
[INFO] [stdout]    |
[INFO] [stdout] 62 |         assert_eq!(reader.fill_buf().unwrap_or_else(|infallible| match infallible {}), &[]);
[INFO] [stdout]    |                    ^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: this type will no longer be must used: Result<&[u8], Infallible>
[INFO] [stdout]   --> src/adapters/chain.rs:63:20
[INFO] [stdout]    |
[INFO] [stdout] 63 |         assert_eq!(reader.fill_buf().unwrap_or_else(|infallible| match infallible {}), &[]);
[INFO] [stdout]    |                    ^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: this type will no longer be must used: Result<&[u8], Infallible>
[INFO] [stdout]   --> src/adapters/chain.rs:69:20
[INFO] [stdout]    |
[INFO] [stdout] 69 |         assert_eq!(reader.fill_buf().unwrap_or_else(|infallible| match infallible {}), &[42]);
[INFO] [stdout]    |                    ^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: this type will no longer be must used: Result<&[u8], Infallible>
[INFO] [stdout]   --> src/adapters/chain.rs:71:20
[INFO] [stdout]    |
[INFO] [stdout] 71 |         assert_eq!(reader.fill_buf().unwrap_or_else(|infallible| match infallible {}), &[]);
[INFO] [stdout]    |                    ^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: this type will no longer be must used: Result<&[u8], Infallible>
[INFO] [stdout]   --> src/adapters/chain.rs:72:20
[INFO] [stdout]    |
[INFO] [stdout] 72 |         assert_eq!(reader.fill_buf().unwrap_or_else(|infallible| match infallible {}), &[]);
[INFO] [stdout]    |                    ^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: this type will no longer be must used: Result<&[u8], Infallible>
[INFO] [stdout]   --> src/adapters/chain.rs:78:20
[INFO] [stdout]    |
[INFO] [stdout] 78 |         assert_eq!(reader.fill_buf().unwrap_or_else(|infallible| match infallible {}), &[42]);
[INFO] [stdout]    |                    ^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: this type will no longer be must used: Result<&[u8], Infallible>
[INFO] [stdout]   --> src/adapters/chain.rs:80:20
[INFO] [stdout]    |
[INFO] [stdout] 80 |         assert_eq!(reader.fill_buf().unwrap_or_else(|infallible| match infallible {}), &[21]);
[INFO] [stdout]    |                    ^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: this type will no longer be must used: Result<&[u8], Infallible>
[INFO] [stdout]   --> src/adapters/chain.rs:82:20
[INFO] [stdout]    |
[INFO] [stdout] 82 |         assert_eq!(reader.fill_buf().unwrap_or_else(|infallible| match infallible {}), &[]);
[INFO] [stdout]    |                    ^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: this type will no longer be must used: Result<&[u8], Infallible>
[INFO] [stdout]   --> src/adapters/chain.rs:83:20
[INFO] [stdout]    |
[INFO] [stdout] 83 |         assert_eq!(reader.fill_buf().unwrap_or_else(|infallible| match infallible {}), &[]);
[INFO] [stdout]    |                    ^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: this type will no longer be must used: Result<&[u8], Infallible>
[INFO] [stdout]   --> src/sync_impls.rs:19:62
[INFO] [stdout]    |
[INFO] [stdout] 19 |       fn fill_buf(&mut self) -> Result<&[u8], Self::ReadError> {
[INFO] [stdout]    |  ______________________________________________________________^
[INFO] [stdout] 20 | |         Ok(*self)
[INFO] [stdout] 21 | |     }
[INFO] [stdout]    | |_____^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: this type will no longer be must used: Result<&[u8], Infallible>
[INFO] [stdout]   --> src/sync_impls.rs:20:9
[INFO] [stdout]    |
[INFO] [stdout] 20 |         Ok(*self)
[INFO] [stdout]    |         ^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: this type will no longer be must used: Result<&[u8], Infallible>
[INFO] [stdout]   --> src/sync_impls.rs:31:62
[INFO] [stdout]    |
[INFO] [stdout] 31 |       fn fill_buf(&mut self) -> Result<&[u8], Self::ReadError> {
[INFO] [stdout]    |  ______________________________________________________________^
[INFO] [stdout] 32 | |         Ok(*self)
[INFO] [stdout] 33 | |     }
[INFO] [stdout]    | |_____^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: this type will no longer be must used: Result<&[u8], Infallible>
[INFO] [stdout]   --> src/sync_impls.rs:32:9
[INFO] [stdout]    |
[INFO] [stdout] 32 |         Ok(*self)
[INFO] [stdout]    |         ^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: this type will no longer be must used: Result<&[u8], Infallible>
[INFO] [stdout]   --> src/sync_impls.rs:76:62
[INFO] [stdout]    |
[INFO] [stdout] 76 |       fn fill_buf(&mut self) -> Result<&[u8], Self::ReadError> {
[INFO] [stdout]    |  ______________________________________________________________^
[INFO] [stdout] 77 | |         Ok(&[])
[INFO] [stdout] 78 | |     }
[INFO] [stdout]    | |_____^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: this type will no longer be must used: Result<&[u8], Infallible>
[INFO] [stdout]   --> src/sync_impls.rs:77:9
[INFO] [stdout]    |
[INFO] [stdout] 77 |         Ok(&[])
[INFO] [stdout]    |         ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: this type will no longer be must used: Result<&[u8], Infallible>
[INFO] [stdout]    --> src/sync_impls.rs:100:62
[INFO] [stdout]     |
[INFO] [stdout] 100 |       fn fill_buf(&mut self) -> Result<&[u8], Self::ReadError> {
[INFO] [stdout]     |  ______________________________________________________________^
[INFO] [stdout] 101 | |         Ok(&[])
[INFO] [stdout] 102 | |     }
[INFO] [stdout]     | |_____^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: this type will no longer be must used: Result<&[u8], Infallible>
[INFO] [stdout]    --> src/sync_impls.rs:101:9
[INFO] [stdout]     |
[INFO] [stdout] 101 |         Ok(&[])
[INFO] [stdout]     |         ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `lgio` (lib test) due to 24 previous errors
[INFO] running `Command { std: "docker" "inspect" "ffd70b0206bb5c2682843ea68850a0614c414af4a830cd0a92e693b1234d71a5", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "ffd70b0206bb5c2682843ea68850a0614c414af4a830cd0a92e693b1234d71a5", kill_on_drop: false }`
[INFO] [stdout] ffd70b0206bb5c2682843ea68850a0614c414af4a830cd0a92e693b1234d71a5